While the use and general form of forks for fork lift vehicles is well known, and a number of different methods of making the same have been availed of, including fabrication as well as forging, the difficulty heretofor has resided in the formation and provision of the main supporting hook portion of the fork, to connect the same to a vehicle and to bear the load, without rupture, this having heretofor been provided by means of a part with a hook element formed therewith welded to the upper end of a fork, in some manner with latch means extending through such member, the fork being supported on a transversely extending rail with notches therein, the latch member being availed of for locking and release permitting movement of fork transversely of the vehicle, forks customarily being used in pairs.
The problem with regard to the latch members, has been that they have usually been in the form of bolt elements, slidable upwardly and downwardly and maintained in position by a spring, the lower end of the bolt engaging a notch on the transverse rail. However the bolt has not heretofor been in position to fully engage with the notch and maintain the same in a completely positive position.
Usually such bolt arrangements are offset enough from the notch so that they do not fully engage the faces of the notches in their respective positions when the fork is positioned on the rail. Movement of the bolt member upwardly under spring pressure will permit movement of the fork but the problem of full engagement of the end has not heretofor been solved.
The inner faces of the notch or notches as the case may be which are formed in the rail upon which the fork is supported, become deformed from use and because of the round shape of the bolt as well as other factors, which interferes with the operation by the operator of the fork for movement from notch to notch along the rail, the deformation causing difficulty in movement of the fork and improper or incomplete engagement of the usual bolt member provided.
Additionally the forms of latch members availed of, have caused many problems, including the difficulty which arises because of rust and other foreign particles surrounding the bolt member per se which will often cause the bolt to become lodged in one position or the other and difficult to release for movement of the fork along the rail as indicated. It is noted that a lower rail is used in conjunction with the upper rail to maintain operative position of the fork, the lower rail not bearing the main weight of the load being carried by the fork or forks as the case may be.
The advantage of availing of a forged head for the fork involving the hook element thereof, will be apparent when it is understood that many of the new regulations and rules relating to safety of vehicles and elements thereof, are not easily met entirely by usual welding processes, which produce connections subject to fracture and to destruction under adverse conditions although not always though the possibility exists and is to be avoided. By availing of forged construction such as is here disclosed, this can largely be overcome if the fork is made in accordance with this invention.